The goals of Core A are to provide cellular and molecular assays in support of all projects. The technologies and methods employed include flow and image cytometry;genetic analyses, cell and tissue culture support and development of common reagents. This Core and its personnel have had a long and productive history of application of specialized cell and molecular assays to the study of Werner Syndrome. These notably include flow and image cytometric assays of cell cycle, survival, DNA damage and telomere status, reagents and assays for Immunologic probes and gene silencing, as well as cell culture support for the broad variety of in vitro assays that is encompassed by this work. Both the characterization of WRN RecQ protein activities and the consequences of these activities on cellular phenotypes thus rely on the use of cell and molecular assays that are used in com man by all of the Projects within this P01 renewal application. The implementation, enhancement and where needed, development of these assays is a service will be most effectively and efficiently performed by this specialized Core in order to optimize their use by the P01 Projects.